5 - Cache pinning is supposed to provide the user with a way of selecting some files from the cache to be permanently updated. This will work very well with disconnected mode because the pinned files will be fresh on disconnection.

23 - Both vcaches and dcaches will get updated in a separate thread (_or_ within the administrative thread). Every _X_ minutes the thread will wake up and do it's job. The expired queue will be emptied by doing `FetchStatus` on vcaches and `FetchData` if needed (for the dcaches). Files get updated in the order that they expire (_like queues usually do :)_).

47 - _sxw_ : avoid callback storms: The simplest version of the callback storm issue is where you have more files pinned in a volume, than the server will grant callbacks. So, every time you get a callback on a new file, a callback on a pinned file is expired. If you aggressively renew callbacks for pinned files, your server loses.

49 - _sxw_ : The critical thing is moving the queue when you start working on it, so any vcaches which are added whilst an update run is in progress get handled in the next run, rather than in the current one. recursion across volume boundaries?

53 - _sxw_ : With extended callbacks we'll be able to tell better whether we've lost a callback because the server won't let us have that many, or if something has really changed. But for now, I think converting pinned -&gt; statd is the best we can do.